imagesc(matrix); title('nxn Matrix Plot'); xlabel('Column Index'); ylabel('Row Index'); colorbar;

You can customize the plot by adding a title, labels, and a colorbar:

By following these steps and tips, you should be able to plot an nxn matrix in MATLAB and save it as a PDF file. Happy plotting!

You can download a free PDF version of this guide: matrix_plot_guide.pdf

Here's the complete example code: